LOST TRACK: An A train at Aqueduct in Queens — the same area where the MTA “misplaced” a train last year. Photo: James Messerschmidt

LOST TRACK: An A train at Aqueduct in Queens — the same area where the MTA “misplaced” a train last year. (James Messerschmidt)

The MTA’s subway boss admitted yesterday that transit officials got so overwhelmed during last year’s Christmastime blizzard they “forgot” about an A train stuck on the tracks for nine agonizing hours with 500 passengers on board.

“We forgot about it, and it’s inexcusable,” NYC Transit President Thomas Prendergast told a City Council hearing yesterday.

To make sure that never happens again, the agency swears it has come up with a host of emergency plans to deal with future blizzards — such as possibly shutting down the system ahead of time.

Prior to the Dec. 26 blizzard that walloped the region, the MTA operated under a “mantra to run at all costs,” he said.

That isn’t so anymore.

“There are times when you change that mantra . . . where it’s clear that you can’t continue top-rate service,” he said at the hearing.

“If you pick people up and you don’t have surety that you’re going to get them to their destination, you have to start curtailing that service.”

After the hearing, he stressed that shutting the system down in its entirety — as the MTA did for Tropical Storm Irene — would not be “taken lightly.”

“You don’t abandon people in need of transportation,” he said.

Not deliberately, at least.

Prendergast admitted that MTA officials became so “overloaded” trying to keep trains operating last December that they forgot about the A train stuck in snow between the Aqueduct and Rockaway Boulevard stations.

Passengers on that train said they were terrified.

“There was no heat. And what if someone was sick or needed medical attention?” said David Jutt, a Scarsdale man who was on the stranded train with his wife and 8-year-old son.